title: Crystallization and preliminary X-ray diffraction studies of D-threo-3-hydroxyaspartate dehydratase isolated from Delftia sp. HT23.
abstract: D-threo-3-Hydroxyaspartate dehydratase (D-THA DH) isolated from the soil bacterium Delftia sp. HT23 is a novel enzyme consisting of 380 amino-acid residues which catalyzes the conversion of D-threo-3-hydroxyaspartate to oxaloacetate and ammonia. D-THA DH also catalyzes the dehydration of L-threo-3-hydroxyaspartate, L-erythro-3-hydroxyaspartate and D-serine. The amino-acid sequence of D-THA DH shows significant similarity to that of two eukaryotic D-serine dehydratases derived from Saccharomyces cerevisiae and chicken kidney. D-THA DH is classified into the fold-type III group of pyridoxal enzymes and is the first example of a fold-type III dehydratase derived from a prokaryote. Overexpression of recombinant D-THA DH was carried out using a Rhodococcus erythropolis expression system and the obtained protein was subsequently purified and crystallized. The crystals of D-THA DH belonged to space group I4₁22, with unit-cell parameters a=b=157.3, c=157.9 Å. Single-wavelength anomalous diffraction data were collected to a resolution of 2.0 Å using synchrotron radiation at the wavelength of the Br K absorption edge.
authors.affiliation: Laboratory of Microbial Physiology, Research Faculty of Agriculture, Hokkaido University, Kita-9, Nishi-9, Kita-ku, Sapporo 060-8589, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Yasutake
authors.forename: Yuki
authors.initials: Y
authors.lastname: Takeda
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Tamura
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yokota
authors.forename: Masaru
authors.initials: M
authors.lastname: Wada
mesh_terms: D055162:Biocatalysis; D003460:Crystallization; D018360:Crystallography, X-Ray; D042742:Delftia / Q000201:enzymology*; D006836:Hydro-Lyases / Q000737:chemistry* / Q000302:isolation & purification*; D014961:X-Ray Diffraction
chemical_list: D006836:Hydro-Lyases
keywords: Br-SAD; Delftia sp. HT23; alanine racemase; d-threo-3-hydroxyaspartate dehydratase; pyridoxal 5′-phosphate